  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 26m 22.21749s [1] |
| Declination | −24° 10′ 31.1190″ [1] |
| Apparent magnitude (V) | 4.16 [2] |
| Characteristics | |
| Spectral type | kA5hA9mF1III [3] |
| U−B color index | +0.12 [4] |
| B−V color index | +0.28 [4] |
| Astrometry | |
| Radial velocity (Rv) | −37.20 [5] km/s |
| Proper motion (μ) |
RA: +0.10
[1]
mas/
yr Dec.: −118.18 [1] mas/ yr |
| Parallax (π) | 39.22 ± 0.24 mas [1] |
| Distance | 83.2 ± 0.5
ly (25.5 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.13 [2] |
| Details | |
| Mass | 1.77 [6] M☉ |
| Radius | 1.9 [7] R☉ |
| Luminosity | 13 [6] L☉ |
| Surface gravity (log g) | 4.15 [8] cgs |
| Temperature | 7,559 [8] K |
| Metallicity [Fe/H] | +0.30 [2] dex |
| Rotational velocity (v sin i) | 78 [6] km/s |
| Age | 1.028 [8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
44 Ophiuchi is a single [10] star in the constellation Ophiuchus. It has the Bayer designation b Ophiuchi, while 44 Ophiuchi is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.16. [2] The distance to this object is approximately 83.2 light years based on parallax. [1] It is drifting closer to the Earth with a heliocentric radial velocity of -37.2 km/s, [5] and is predicted to come within 30 light-years around 585,000 years from now. [11]
This is an Am star with a stellar classification of kA5hA9mF1III, [3] indicating it has the luminosity class of a giant star with a spectrum that matches an A5 star based on the calcium K line, and an A9 star from the hydrogen and metal lines. It is around a billion years old [8] with 1.77 [6] times the mass of the Sun and 1.9 [7] times the Sun's girth. The star is radiating 13 [6] times the Sun's luminosity from its photosphere at an effective temperature of 7,559 K. [8] It retains a moderately high rotation rate, showing a projected rotational velocity of 78 km/s. [6]
References
- ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
- ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
- ^ a b Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv: astro-ph/0603770. Bibcode: 2006AJ....132..161G. doi: 10.1086/504637. S2CID 119476992.
- ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode: 2014JAVSO..42..443M. Vizier catalog entry
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053. Bibcode: 2006AstL...32..759G. doi: 10.1134/S1063773706110065. S2CID 119231169.
- ^ a b c d e f Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv: 1201.2052. Bibcode: 2012A&A...537A.120Z. doi: 10.1051/0004-6361/201117691. S2CID 55586789. Vizier catalog entry
- ^ a b Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv: astro-ph/9911002. Bibcode: 1999A&A...352..555A. Vizier catalog entry
- ^ a b c d e David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv: 1501.03154. Bibcode: 2015ApJ...804..146D. doi: 10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry
- ^ "b Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-06-21.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv: 0806.2878. Bibcode: 2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ Bailer-Jones, C. A. L. (March 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: 13. arXiv: 1412.3648. Bibcode: 2015A&A...575A..35B. doi: 10.1051/0004-6361/201425221. S2CID 59039482. A35.
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 26m 22.21749s [1] |
| Declination | −24° 10′ 31.1190″ [1] |
| Apparent magnitude (V) | 4.16 [2] |
| Characteristics | |
| Spectral type | kA5hA9mF1III [3] |
| U−B color index | +0.12 [4] |
| B−V color index | +0.28 [4] |
| Astrometry | |
| Radial velocity (Rv) | −37.20 [5] km/s |
| Proper motion (μ) |
RA: +0.10
[1]
mas/
yr Dec.: −118.18 [1] mas/ yr |
| Parallax (π) | 39.22 ± 0.24 mas [1] |
| Distance | 83.2 ± 0.5
ly (25.5 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.13 [2] |
| Details | |
| Mass | 1.77 [6] M☉ |
| Radius | 1.9 [7] R☉ |
| Luminosity | 13 [6] L☉ |
| Surface gravity (log g) | 4.15 [8] cgs |
| Temperature | 7,559 [8] K |
| Metallicity [Fe/H] | +0.30 [2] dex |
| Rotational velocity (v sin i) | 78 [6] km/s |
| Age | 1.028 [8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
44 Ophiuchi is a single [10] star in the constellation Ophiuchus. It has the Bayer designation b Ophiuchi, while 44 Ophiuchi is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.16. [2] The distance to this object is approximately 83.2 light years based on parallax. [1] It is drifting closer to the Earth with a heliocentric radial velocity of -37.2 km/s, [5] and is predicted to come within 30 light-years around 585,000 years from now. [11]
This is an Am star with a stellar classification of kA5hA9mF1III, [3] indicating it has the luminosity class of a giant star with a spectrum that matches an A5 star based on the calcium K line, and an A9 star from the hydrogen and metal lines. It is around a billion years old [8] with 1.77 [6] times the mass of the Sun and 1.9 [7] times the Sun's girth. The star is radiating 13 [6] times the Sun's luminosity from its photosphere at an effective temperature of 7,559 K. [8] It retains a moderately high rotation rate, showing a projected rotational velocity of 78 km/s. [6]
References
- ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
- ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
- ^ a b Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv: astro-ph/0603770. Bibcode: 2006AJ....132..161G. doi: 10.1086/504637. S2CID 119476992.
- ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode: 2014JAVSO..42..443M. Vizier catalog entry
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053. Bibcode: 2006AstL...32..759G. doi: 10.1134/S1063773706110065. S2CID 119231169.
- ^ a b c d e f Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv: 1201.2052. Bibcode: 2012A&A...537A.120Z. doi: 10.1051/0004-6361/201117691. S2CID 55586789. Vizier catalog entry
- ^ a b Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv: astro-ph/9911002. Bibcode: 1999A&A...352..555A. Vizier catalog entry
- ^ a b c d e David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv: 1501.03154. Bibcode: 2015ApJ...804..146D. doi: 10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry
- ^ "b Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-06-21.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv: 0806.2878. Bibcode: 2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ Bailer-Jones, C. A. L. (March 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: 13. arXiv: 1412.3648. Bibcode: 2015A&A...575A..35B. doi: 10.1051/0004-6361/201425221. S2CID 59039482. A35.
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